RMClock reads the current processor speed (aka. SpeedStep/Coolnquiet) and C-state and
shows you the corresponding voltage level according to the datasheet(s). And I remember
back in the early Pentium-M days, Intel had 4 voltages listed for a single speed state, depending
on CPU bin number (which only the OEM could determine). So don't read too much into RMClock "results".

PCIe, PCI, Cardbus and USB devices are required to provide vendor and device IDs that can be read to inform you of whats there.
ISA devices never had this functionality, but they pretended it existed after plug and pray was grafted on.

SMBus is a simple bus like ISA. There is no auto detection, you can detect the existance of a device on the bus but not what it does.
Determining what it does is down to hueristics that don't always work. Did you see the sensors detect warning that it might hang your system?

It doesn't matter if i2c_i801 is loaded as a loadable module or built into the kernel. It works the same way._________________Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Do you want to read the actual voltage from a sensor or read the requested voltage by the CPU?

Few laptops offer software-facing sensors for this sort of thing yours very likely doesn't. But the latter is possible through the CPU's MSRs (machine specific registers). RMClock does the same. To do that, you'll need rdmsr from msr-tools (which for some reason is not in portage) and the msr module in the kernel.
msr-tools should be trivial to compile manually. Here are the sources

You can then, as root, read the CPU's MSR.

Code:

# rdmsr -0 0x198
061b4c2686004b26

This reads register 0x198 from the first CPU. The current voltage ID (VID) is in hexadecimal the last 2 digits and might fluctuate with the core clock if Speedstep is enabled.
In my case it is 26, or 38 in decimal. On a mobile Core2Duo, the formula is 0.7125V + VID*0.0125V. In my case that corresponds to 1.1875V. (keep in mind that VID is in hex! desktop CPUs use another formula, too)